Upgrading and Repairing
PCs
Serial and Parallel Ports
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Serial interface transmits data over a
single wire, one bit at a time |
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Also uses start and stop bits |
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A serial line can be up to 50 feet |
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Parallel interface transmits data over
8 wires, one byte at a time |
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No stop and start bits |
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A parallel line can be up to 10 feet |
Serial and Parallel Port
Replacements
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USB (Universal Serial Bus) |
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Allows for up to 127 devices to be
daisy chained |
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1.5Mb per sec |
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Used for low bandwidth devices (mice,
etc) |
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USB
10 times as fast suitable even for external HD can use USB 1 devices
on USB 2 ports |
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FireWire (IEEE-1394 or i.LINK) |
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Up to 400Mb per second |
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Used for High bandwidth devices (drive
units) |
Input Devices
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Keyboards |
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Many designs available, most popular is
the 104 key Windows keyboard |
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Mouse |
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Used in GUI (Graphical User Interface)
environments |
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Became popular after Apple released the
Macintosh |
Memory Readers
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New flash memory devices and cards for |
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Cameras |
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MP3 Players |
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Video Recorders |
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Readers for SD, and other types can be
installed in the PC or device must be hooked up via firewire or USB |
Other Pointing Interfaces
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Intellimouse/Scrollpoint |
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Has a scroll wheel on the mouse |
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Trackpoint |
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Rubber cap found in laptops between the
G and H keys on the keyboard |
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Glidepoint/Trackpads |
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Touchpad interface found in laptops and
wireless keyboards |
Audio Hardware
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Most are SoundBlaster compatible |
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Adds multimedia capabilities to a PC |
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Game port is usually attached to sound
card |
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Many file formats available |
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RA (Real Audio) |
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WAV |
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MP3 |
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Wavetable Synthesis
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Replaces FM synthesis found in older
cards |
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Modern standard for sound cards |
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Samples of sound are taken from common
instruments and then stored in a ROM chip on the card or in a share part of
the PCs memory |
Video Hardware
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Monitor technologies available today |
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CRT (Cathode Ray Tube) |
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LCD (Liquid Crystal Display) |
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Plasma |
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Video adapters |
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Convert digital data into analog data |
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Many have onboard microprocessors and
memory for video acceleration |
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Monitors
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Characteristics to look for in a
monitor |
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Refresh rate (70Hz or better is
considered “flicker free” |
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Size |
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Maximum resolution |
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Dot pitch |
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Non interlaced |
Video Cards
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Characteristics to look for in a video
card |
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AGP (Accelerated Graphics Port)
interface |
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Memory (both speed and amount) |
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Maximum refresh rate |
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3D acceleration |